1. Field of the Invention
This invention relates generally to exercising apparatus and more particularly to a unique safety improvement in exercising machines of the type wherein the body-engaging means or lifting arm is telescopically interconnected with a downwardly biased vertically reciprocative carriage.
2. Discussion of the Prior Art
In exercising machines of the type described in U.S. Pat. Nos. 3,635,472 and 3,971,555, there is provided an upright supporting structure having vertical track means, a vertically reciprocative carriage guided by the track means, weight means connected to the carriage to bias it downwardly and body-engaging means in the form of a lifting arm which is releasably interconnected to the carriage. In these devices, to accomodate different lifting arm starting heights the carriage is provided with a plurality of vertically spaced apart sockets adapted to telescopically receive a socket-engaging portion formed on the lifting arm. The lifting arm itself comprises, in addition to the socket-engaging portion, handle portions forming a "V" with the socket-engaging portion. The handle portions lie in a plane above the plane in which the socket-engaging portion is disposed. The lifting arm thusly configured coacts with the vertically spaced sockets to provide a plurality of starting heights. Additionally, by inverting the lifting arm so that the handle portions lie in a plane below that of the socket-engaging portion, further adjustment in vertical starting height is possible.
In the machines described in the aforementioned patents, as well as in various other similar types of machines, the lifting arm is typically locked against accidental removal from the sockets by means of a removable pin which extends through the socket and the socket-engaging portion of the lifting arm. This arrangement has proved disadvantageous for several reasons. For example, in practice the user of the apparatus may lose the pin or neglect or forget to insert it into the socket after the lifting arm is inserted. Additionally, the locking pin may become worn through use and become susceptible to failure under load. If the pin fails or is not properly in place, when the carriage is lifted the lifting arm may accidentally slip from the socket, causing severe injury to the user of the machine.
The unique safety latching device of the present invention overcomes the aforementioned drawbacks of the pin lock arrangement by providing a failsafe mechanism for automatically interlocking the lifting arm and the carriage upon insertion of the lifting arm into the carriage socket. The latching mechanism of the present invention is integral with the lifting arm so that it cannot be lost. It is structurally extremely sturdy so that it will not fail during use. Additionally, it is constructed so as to automatically and positively fall into locking engagement with the carriage by force of gravity upon insertion of the lifting arm into position relative to the carriage.